1. Field of the Invention
The present invention relates to a handle attachment structure for a bag, such as a briefcase and a suitcase.
Priority is claimed on Japanese Patent Application No. 2002-286187, filed Sep. 30, 2002, the content of which is incorporated herein by reference.
2. Description of Related Art
In general, a handle for a bag, which is formed in a substantially U-shape, is rotatably supported by attachments for attaching the handle to a bag body in such a manner that each of the ends of the handle is held by each of the attachments using a handle spindle.
In a general handle attachment structure for a bag shown, for example, in FIG. 3, a through hole 11 having a predetermined diameter is formed in an end 10 of a handle 1, and on the other hand, spindle holes 3 into which a handle spindle 4 is inserted are formed in an attachment 2. The spindle holes 3 is bored from one side of the attachment 2 so as to cross over an engagement recess 20 of the attachment 2, into which the end 10 is to be inserted. In an assembling process for making the handle 1 to be rotatably supported, the through hole 11 and the spindle holes 3 are aligned to each other in the engagement recess 20, and then the handle spindle 4 is inserted from an insertion aperture 31 so as to have an interference fit with the spindle holes 3 by, for example, hammering.
In this case, the inner surfaces of the spindle holes 3 and the outer surface of the handle spindle 4 are precision finished in order to ensure friction therebetween due to insertion and to prevent the handle spindle 4 from coming off the spindle holes 3. When it is necessary, the handle spindle 4 is provided with knurling on the surface near the proximal end thereof.
Alternatively, in some cases, the spindle holes 3 and the handle spindle 4 are provided with screw surfaces thereon, and the handle spindle 4 is screwed into the spindle holes 3.
Many other proposals have been made with regard to handle attachment structures in which handle spindles are used. An example is disclosed in Japanese Examined Utility Model Application, Second Publication No. Hei 01-31063 (Reference 1), in which a reinforcing frame having an elastic piece of metal is provided in order to strengthen a portion for attachment, and the elastic piece prevents a handle spindle from coming off. Another example is disclosed in Japanese Unexamined Utility Model Application, First Publication No. Hei 02-86318 (Reference 2), in which separate attachments are provided, and an end of handle, through which a handle spindle is inserted, is held between the attachments so that the handle is fixed to a bag body. A further example is disclosed in Japanese Unexamined Patent Application, First Publication No. Hei 08-205919 (Reference 3), in which separate attachments including a fixed supporting piece and a movable supporting piece are provided, and a handle spindle having a spring thereon is inserted from the movable supporting piece side so that the movable supporting piece is biased toward an end of a handle, and so that the handle is held in a standing state.
In the conventional handle attachment structure shown in FIG. 3, because the handle spindle and the spindle holes must be precision finished, the manufacturing cost is increased, and reliability may be degraded due to poor assembly in the assembling process and due to variations of accuracy in finishing.
Moreover, the above handle attachment structure also has a problem in terms of strength during use. More specifically, because the handle spindle supports the weight of the bag body and vibrations during use are applied thereto, the handle spindle tends to loosen in the spindle holes due to vibrations and impacts, and, in the worst case scenario the handle spindle may come out of the spindle holes, and the handle attachment structure may be broken, which would require time consuming repair.
In the attachment structures disclosed in References 1 to 3, problems are encountered in that the structures are relatively complex. More specifically, a reinforcing element may be required to ensure strength of a portion for attaching the handle, or manufacturing cost is relatively high because many elements are included and many assembling steps are required due to the separate attachments. Moreover, a problem may be encountered in strength during use as mentioned above.